Tried installing gems as said in the readme but it fails both on ruby 1.9.3-p551 and 2.2.2
$ RAILS_VERSION=4.1.2 bundle install
Your Gemfile lists the gem poltergeist (>= 0) more than once.
You should probably keep only one of them.
While it's not a problem now, it could cause errors if you change the version of just one of them later.
Fetching git://github.com/rails/sass-rails.git
Fetching gem metadata from https://rubygems.org/...........
Fetching additional metadata from https://rubygems.org/..
Resolving dependencies...
Could not find gem 'sprockets (>= 4.0) ruby', which is required by gem 'sass-rails (>= 0) ruby', in any of the sources.
Tried installing gems as said in the readme but it fails both on ruby 1.9.3-p551 and 2.2.2